Punch with groove structure, and micro-drawing device using the same

ABSTRACT

Provided is a micro-drawing device using punch having groove structure. The micro-drawing device includes a first die base assembly, a second die base assembly and a punch. The first die base assembly includes a fixing part; a position of the second die base assembly is corresponding to a position of the first die base assembly, and the second die base assembly includes a die cavity part; and the punch includes a fixing end and a work piece processing end, wherein a position of the work piece processing end is corresponding to a position of the fixing end, the fixing end is used to be disposed at the fixing part, and the work piece processing end faces the die cavity part; wherein, a plurality of grooves is provided at a peripheral surface of the work piece processing end. The present invention also discloses a punch having groove structure.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Taiwan Patent Application No. 100138245, filed on Oct. 21, 2011, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

1. Field of Invention

The present invention relates to a micro-drawing device, and more particularly to a micro-drawing device having a punch provided with groove structure.

2. Related Art

Drawing process employs drawing die to stamp a blank in order to obtain desired product shape. Please refer to FIGS. 1A and 1B, wherein FIG. 1A is a view illustrating the status before the blank is processed by the punch of a micro-drawing device according to the prior art; and FIG. 1B is a view illustrating the status after the blank is processed by the punch of the micro-drawing device shown in FIG. 1A.

As shown in FIGS. 1A and 1B, the micro-drawing device 6 includes a blank holder 60, a die cavity 61, and a punch 62. When performing drawing process, a blank P may be placed between the die cavity 61 and the blank holder 60; the blank holder 60 holds the blank P with a blank-holding force F, while the punch 62 gradually entering into the die cavity 61, allowing the blank P to be filled inside the die cavity 61, and thereby finishing the drawing process.

However, owing to the design of the punch 62 according to the prior art, as shown in FIG. 1B, when the blank P is drawn and formed, there may exist a problem of different thickness at the upper round corner R1 and the lower round corner R2 of the resulting product. For example, the thickness W2 of the lower round corner R2 may be smaller than the thickness W1 of the upper round corner R1. In more detail, due to the partial force applied to the lower round corner R2, the thickness W2 of the lower round corner R2 is hence smaller than the thickness W1 of the upper round corner R1; therefore, a fracture is more likely to occur at the lower round corner R2. Further, the thickness W1 of the upper round corner R1 increases when getting closer to the blank holder 60; therefore, a wrinkle is more likely to appear.

SUMMARY

In order to overcome the deficiencies of the prior art, the present invention provides a punch with groove structure and a micro-drawing device using the same.

With the above objective in mind, the present invention provides a punch with groove structure, which includes a main body, and a plurality of grooves is provided at a peripheral surface of a work piece processing end thereof.

With the above objective in mind, the present invention further provides a micro-drawing device using the punch with groove structure. The micro-drawing device includes a first die base assembly, a second die base assembly, and a punch. The first die base assembly includes a fixing part; a position of the second die base assembly is corresponding to a position of the first die base assembly, and the second die base assembly includes a die cavity part; and the punch includes a fixing end and a work piece processing end, wherein a position of the work piece processing end is corresponding to a position of the fixing end, the fixing end is used to be disposed at the fixing part, and the work piece processing end faces the die cavity part; wherein, a plurality of grooves is provided at a peripheral surface of the work piece processing end.

The feature of the present invention is in that: unlike the design according to the prior art, the punch with groove structure and the micro-drawing device using the same provided by the present invention may, when the punch is performing drawing process to the blank, use the plurality of grooves disposed at the peripheral surface of the work piece processing end of the punch main body to more ensure uniformity of thickness of the final product (including the thickness of upper round corner and lower round corner).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a view illustrating the status before blank is processed by the punch of the micro-drawing device according to the prior art;

FIG. 1B is a view illustrating the status after the blank is processed by the punch of the micro-drawing device shown in FIG. 1A;

FIG. 2A is a view illustrating the status before blank is processed by the punch with groove structure of the micro-drawing device according to an embodiment of the present invention;

FIG. 2B is a view illustrating the status after the blank is processed by the punch shown in FIG. 2A;

FIG. 2C is a view illustrating a plurality of grooves provided at a peripheral surface of a work piece processing end of the punch shown in FIG. 2A, and it provide drawing and friction force to allow the blank to be drawn more uniformly;

FIG. 2D is a view illustrating a triangular cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention;

FIG. 2E is a view illustrating a trapezoidal cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention;

FIG. 2F is a view illustrating a semi-circular cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention;

FIG. 2G is a view illustrating an irregular cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention; and

FIG. 3 is a view illustrating a punch with a cone shaped structure of a micro-drawing device according to another embodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiment of the present disclosure, examples of which are illustrated in the accompanying drawings.

Please refer to FIG. 2A, which is a view illustrating the status before blank is processed by the punch with groove structure of the micro-drawing device according to an embodiment of the present invention.

As shown in FIG. 2A, a micro-drawing device 1 having a punch with groove structure (hereinafter referred as micro-drawing device) includes a first die base assembly 11, a second die base assembly 12, and a punch 13.

The first die base assembly 11 includes a fixing part 110. A position of the second die base assembly 12 is corresponding to a position of the first die base assembly 11, and the second die base assembly 12 includes a die cavity part 120. The first die base assembly 11 according to the present embodiment may be an upper die base assembly, and the second die base assembly 12 may be a lower die base assembly. However, the present invention is not limited thereto, and may vary according to actual design requirement.

The punch 13 includes a fixing end 131 and a work piece processing end 132, wherein a position of the work piece processing end 132 is corresponding to a position of the fixing end 131, the fixing end 131 is used to be disposed at the fixing part 110, and after the fixing end 131 is disposed at the fixing part 110, the work piece processing end 132 faces the die cavity part 120. Wherein, a plurality of grooves 133 is provided at a peripheral surface S of the work piece processing end 132, and there is an interval D between each of the grooves 133, as shown in FIG. 2C. Alternatively, the grooves 133 may be formed as a whole and spirally extending on the peripheral surface S. the punch 13 (including the plurality of grooves 133) may be fabricated using a micro-machining equipment (not shown), but is not limited thereto.

In detail, the first die base assembly 11 may further include a plurality of bolt members 111 and a blank holder 112 corresponding to the die cavity part 120. Wherein, each of the bolt members 111 has a same height and is disposed of a flexible member 113 (such as a spring). The bolt members 111 are sandwiched between the fixing part 110 and the blank holder 112 using the corresponding flexible member 113.

Preferably, a guide post 14 for closing or opening die in the micro-drawing device 1 may be further provided between the first die base assembly 11 and the second die base assembly 12. And a guide post bushing cover 15 may be further included to prevent the first die base assembly 11 and/or the second die base assembly 12 from directly contacting the guide post 14 in order to avoid damage thereof, thereby protecting the guide post 14.

The fixing part 110 may further include a punch back plate 110 a, a punch fixing plate 110 b, and a fixing member used to attach the punch back plate 110 a to the punch fixing plate 110 b. The fixing member may consist of at least one positioning pin 114 a and at least one bolt 114 b. Wherein, the fixing end 131 of the punch 13 may be pressed against the punch back plate 110 a and positioned at the punch fixing plate 110 b. Further, the die cavity part 120 may further include a die cavity back plate 120 a and a die cavity 120 b provided on the die cavity back plate 120 a. Similarly, the second die base assembly 12 may include a fixing member to fix the die cavity back plate 120 a, wherein the fixing member of the second die base assembly 12 may consist of at least one positioning pin 121 a and at least one bolt 121 b.

Please refer to FIGS. 2A to 2C. FIG. 2B is a view illustrating the status after the blank is processed by the punch shown in FIG. 2A; and FIG. 2C is a view illustrating a plurality of grooves provided at a peripheral surface of a work piece processing end of the punch shown in FIG. 2A, and it provide drawing and friction force to allow the blank to be drawn more uniformly.

As shown in FIG. 2A, when performing drawing process on blank 20, the blank (such as blank material) is positioned between the blank holder 112 and the die cavity 120 b. As the micro-drawing device 1 is driven, the guide post 14 may guide the first die base assembly 11 to move closer to the second die base assembly 12. At this time, as shown in FIG. 2B, the flexible member 113 between the fixing part 110 and the blank holder 112 is compressed (in other words, the micro-drawing device 1 is in a die closing status).

Then, as the punch 13 is performing drawing process on the blank 20, the grooves 133 of the peripheral surface S of the work piece processing end 132 (there is an interval D between each of the grooves 133) may sequentially provide a drawing and friction force F following the force-applying downward direction of the punch 13. This allows a thickness W1 of an upper round corner R1 of the blank 20 to be drawn downwards (please refer to FIG. 2C), which means that the thickness W1 of the upper round corner R1 will not be thickened, and the wrinkle problem may be prevented. Further, since the extra thickness is moved to the lower round corner R2, the thickness W1 of the upper round corner R1, the thickness W2 of the lower round corner R2, and the thickness between the two round corners may more remain uniformity, thereby improving the whole quality of the blank 20 after the drawing process. After the micro-drawing device 1 is in a die opening status, the blank 20 being drawn and formed and having more uniform thickness may be obtained.

Please refer to FIGS. 2D to 2F, wherein FIG. 2D is a view illustrating a triangular cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention; FIG. 2E is a view illustrating a trapezoidal cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention; and FIG. 2F is a view illustrating a semi-circular cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention.

As shown in FIGS. 2D to 2F, the cross section of the plurality of grooves of the peripheral surface S of the work piece processing end of the punch may be a regular shape. For example, the plurality of grooves 133 a of the punch 13 a shown in FIG. 2D may have a triangular cross section; the plurality of grooves 133 b of the punch 13 b shown in FIG. 2E may have a trapezoidal cross section; and the plurality of grooves 133 c of the punch 13 c shown in FIG. 2F may have a semi-circular or semi-elliptical (arc- or wave-shaped) cross section.

Of course, with different designs, the cross section of the plurality of grooves of the peripheral surface of the work piece processing end of the punch may include regular, irregular, or other geometric shapes, and is not limited to the disclosure shown in FIGS. 2D to 2F.

Please refer to FIG. 2G, wherein FIG. 2G is a view illustrating an irregular cross section of a plurality of grooves provided at the work piece processing end of the punch of the micro-drawing device according to another embodiment of the present invention.

As shown in FIG. 2G, the cross section of the plurality of grooves of the peripheral surface of the work piece processing end of the punch may be an irregular shape. For example, the plurality of grooves 133 d of the punch 13 d shown in FIG. 2G may have an irregular cross section. The irregular shape includes a plurality of lines and curves.

Thus, the thickness of the drawn blank may more remain uniformity, thereby improving the product quality.

Please refer to FIG. 3, which is a view illustrating a punch with a cone-shaped structure of a micro-drawing device according to another embodiment of the present invention.

As shown in FIG. 3 (please refer to the enlarged view at the right), the punch 2 is of a cone shape, which means that the punch 2 is thicker at the fixing end 231 and thinner at the work piece processing end 232. A plurality of grooves 233 is included at the peripheral surface S2 of the work piece processing end 232, and there is an interval between each of the grooves 233. Alternatively, the grooves 233 may be formed as a whole and spirally extending on the peripheral surface S2.

With the punch 2 that has a cone-shaped structure, thickness W3 of an upper round corner R3 of the blank 30 may be drawn downwards gradually and more rapidly, which means that the thickness W3 of the upper round corner R3 will not be thickened, and the wrinkle problem may be prevented. Further, since the extra thickness is moved to a lower round corner R4, the thickness W3 of the upper round corner R3, the thickness W4 of the lower round corner R4 and the thickness between the two round corners may more remain uniformity, thereby improving the whole quality of the blank 30 after the drawing process.

As the foregoing, the punch with groove structure and a micro-drawing device using the same according to the present invention have features as described below.

1. As the punch is performing drawing process on the blank, the plurality of grooves of the peripheral surface of the work piece processing end may sequentially provide a drawing and friction force following the force-applying downward direction of the punch. This allows a thickness of an upper round corner of the blank to be drawn downwards, which means that the thickness of the upper round corner will not be thickened, and the wrinkle problem may be prevented. Further, since the extra thickness is moved to a lower round corner, the thickness of the upper round corner, the thickness of the lower round corner and the thickness between the two round corners may more remain uniformity, thereby improving the whole quality of the blank after the drawing process.

2. With the punch that has a cone-shaped structure, thickness of the upper round corner of the blank may be drawn downwards gradually and more rapidly.

3. A cross section of the plurality of grooves of the peripheral surface of the work piece processing end of the punch may include regular, irregular, or other geometric shapes.

The previous description of the preferred embodiment is provided to further describe the present invention, not intended to limit the present invention. Any modification apparent to those skilled in the art according to the disclosure within the scope will be construed as being included in the present invention. 

What is claimed is:
 1. A punch with groove structure, comprising: a main body, wherein a plurality of grooves is provided at a peripheral surface of a work piece processing end of the main body.
 2. The punch with groove structure according to claim 1, wherein an interval is disposed between each of the grooves.
 3. The punch with groove structure according to claim 1, wherein the plurality of grooves is formed on the peripheral surface in spirally extending.
 4. The punch with groove structure according to claim 1, wherein the main body is of a cone-shaped structure.
 5. The punch with groove structure according to claim 1, wherein a cross section of the plurality of grooves is a regular shape.
 6. The punch with groove structure according to claim 5, wherein the regular shape includes a triangular, rectangular, trapezoidal, semi-elliptical or semi-circular shape.
 7. The punch with groove structure according to claim 1, wherein a cross section of the plurality of grooves is an irregular shape.
 8. A micro-drawing device using a punch with groove structure, comprising: a first die base assembly including a fixing part; a second die base assembly, a position of the second die base assembly corresponding to a position of the first die base assembly, and includes a die cavity part; and a punch, including a fixing end and a work piece processing end, wherein a position of the work piece processing end is corresponding to a position of the fixing end, the fixing end is used to be disposed at the fixing part, and the work piece processing end faces the die cavity part, and a plurality of grooves is provided at a peripheral surface of the work piece processing end.
 9. The micro-drawing device according to claim 8, wherein the first die base assembly further includes a plurality of bolt members and a blank holder corresponding to the die cavity part; each of the bolt members is disposed of a flexible member, and the bolt members are sandwiched between the fixing part and the blank holder using the corresponding flexible member.
 10. The micro-drawing device according to claim 9, wherein a guide post is further provided between the first die base assembly and the second die base assembly, and the first die base assembly further includes a guide post bushing cover corresponding to the guide post.
 11. The micro-drawing device according to claim 9, wherein the fixing part further includes a punch back plate, a punch fixing plate, and a fixing member used to attach the punch back plate to the punch fixing plate; wherein, the fixing end of the punch may be pressed against the punch back plate and positioned at the punch fixing plate.
 12. The micro-drawing device according to claim 9, wherein the die cavity part further includes a die cavity back plate and a die cavity provided on the die cavity back plate.
 13. The micro-drawing device according to claim 8, wherein an interval is disposed between each of the grooves.
 14. The micro-drawing device according to claim 8, wherein the plurality of grooves is formed on the peripheral surface in spirally extending.
 15. The micro-drawing device according to claim 8, wherein the punch is a cone-shaped structure.
 16. The micro-drawing device according to claim 8, wherein a cross section of the plurality of grooves is a regular shape.
 17. The micro-drawing device according to claim 16, wherein the regular shape includes a triangular, rectangular, trapezoidal, semi-elliptical or semi-circular shape.
 18. The micro-drawing device according to claim 8, wherein a cross section of the plurality of grooves is an irregular shape. 